Tuning Maverick leak

[sloanshannon1]

Brand new Maverick pre “tuned” from retailer and shipped off with a tank full of air. This was great considering I was still waiting on my compressor. 
Man this thing shoots like a dream. Going from a nitro piston style to a quality PCP has been a beautiful but somewhat bitter experience….



By the time that first tank of air was depleted my compressor head came in. So I connected the air compressor charge the tank back up to 230+ bar and walked outside and started shooting. Heck yeah. But I also planned on adjusting the reg settings because I had purchased some new ammo and was looking to fine-tune it. So I followed the direction of the same YouTuber we all watch at some point or another (MD) and followed his instructions to the T. I also kind of cross-referenced those with what was in the literature sent with the rifle. 

So I removed the tank, and bled the rifle, and closed the the 1st reg(clockwise) and then opened up the second regulator to flush or a bit under. But when I went to screw the bottle back on and introduced air back into the Plenum to read the first regulators pressure on the gauge in the back air started leaking out as fast as I allowed it to come out of the first regulator. It took me a minute to figure out exactly where it was coming from but I learned it was coming from the hole on the valve pin retaining cap. Keep in mind this is a brand new rifle from the factory that I had never disassembled. The only adjustment I made was what I described when I went to change the regulator setting. I have searched high and low on forums and YouTube videos and have not found one other person that has experienced this issue. Fast forward a few days and I have had this rifle apart many times looking for inconsistencies or some thing I was missing…



-The air is clearly coming from the Hole on the valve pin (C57) retaining tap. (C57 through C63) are assembled correctly. But I also spent detailed time inspecting the valve seat as Ernest suggested in the masterclass. The valve seat is correct.



-To me, it would seem the valve pin and seat would be the problem if the air was leaking out of the barrel? There is a small chamber in the main block where the air comes in from the plenum. It seems this is where the air should seal. Until the hammer releases the valve pin forward when fired releasing the regulated air. It is there in that chamber air is not being held. It seems C62, C60, and C59 assembly are not sealing correctly on the inside of C57 around that pin center hole. Because as soon as I release air from the first regulator the air will NOT hold at the center hole of C57.



I attached a photo showing exactly where the air is coming from.



but just as an update I was able to figure out what the problem is but I just want to know if anybody else has had the same issue and what it ended up being. I was able to get it to hold air and it will work until FX send me replacement parts but this is been an unfortunate experience. But the fact that I have not been able to find anyone else with the same problem just reinforces my understanding that sometimes crap just happens…to me haha

 

[tor47]

Did you somehow forget to check regpressure, and shot the gun down to low pressure? The reason I ask is that if the valve overtravels, you might damage something. Think there should be a small O-ring in there somewhere.

 

[sloanshannon1]

Thank you for your response but no, instructions and best practices were followed. But furthermore the regulators are/were fine, there is a chamber as soon as the plenum enters the main block where air is not/will not hold air.

 

[sloanshannon1]

So just to close this open ended thread for the record…

Upon close inspection of the replacement parts from FX I learned there was a small production error in the valve stem retaining cap (57). The small spring seat(60) was not able to engage the small o-ring(59) enough to seal the hole on the end of the retaining cap(57) when that assembly is installed on to the end of the valve pin.

Meaning, the inside of the retaining cap(57) did not have the proper relief machined out of the inside for the spring seat(60) and o-ring(59) assembly to do intended purpose.

As I said, a one off issue. This was unfortunate and frustrating at times but it did however help me to become painstakingly familiar with the internals and engineering of Maverick. Also, I knew when buying a tactical airgun like the Maverick there would be challenges to overcome. 


These days I’m throwing lead slugs around at blitzing speeds and have become a happy camper.